Prepare Your Broccoli

Start by cutting fresh broccoli into bite-sized florets. Steam them for about five minutes until they're bright green and slightly tender but still have a bit of crunch. You don't want mushy broccoli in your finished casserole.

Create the Creamy Base

In a large mixing bowl, combine the cream of mushroom soup, sour cream, mayonnaise, shredded cheddar cheese, minced onion, and garlic powder. Stir everything together until smooth and well incorporated. This creamy mixture is what makes the casserole so addictively delicious.

Combine and Season

Drain your steamed broccoli well and add it to the creamy mixture. Fold gently until every piece of broccoli is coated in that rich, cheesy sauce. Season with salt and black pepper to taste, remembering that the cheese adds saltiness too.

Assemble in Baking Dish

Transfer everything to a greased nine-by-thirteen-inch baking dish, spreading it evenly. This size ensures the casserole cooks through perfectly while developing that beautiful golden top.

Prepare the Topping

Melt butter and toss it with breadcrumbs and additional shredded cheese. This creates those irresistible crispy bits that everyone fights over. Sprinkle this mixture generously over your casserole.

Bake to Perfection

Bake in a preheated oven at three hundred fifty degrees Fahrenheit for thirty to thirty-five minutes. You'll know it's ready when the edges bubble enthusiastically and the top turns golden brown and crispy.